I remember a similar thread which was created a few years back. We debated for many months, and in the end the thread died without any solid solution to the issue. IMO, the only solution that is going to be acceptable to all is a decision by the UN. But it needs to be seen whether the Chinese will accept it.
Here is a copy of the "Award in the 'South China Sea Arbitration- PCA-CPA" though I don't suggest reading it since its 479 pages:
https://pca-cpa.org/wp-content/uploads/sites/175/2016/07/PH-CN-20160712-Award.pdfIn summary, the disputed reefs are not classified as habitable, the seas are considered as traditional fishing grounds. All surrounding countries have the right to fish there peacefully(supposedly). Militarization was illegal(but they didn't say that it should be removed) and there should be no harassment on fishermen there(but in some news, there is). The award itself has no teeth.
The problem arises whenever there is military action happening, on either US, China, (or Vietnam), they are considerably the most active there in terms of "freedom of navigation" and military activities, as said in the article.